Implantable medical devices (IMDs) are used to deliver therapy to patients for the treatment of a variety of symptoms or conditions. Examples include implantable stimulators, such as an implantable neurostimulator, a cardiac pacemaker, an implantable cardioverter-defibrillator (ICD), and implantable fluid delivery devices. Each IMD typically delivers therapy according to a number of programmable parameters. For example, for a neurostimulator, a clinician may select a pulse amplitude, which may be a current or voltage amplitude, a pulse width, a pulse rate, a pulse profile (e.g., number of pulses per burst and the number of bursts over a period of time), the electrode or electrodes from which pulses may be delivered, as well as the polarities of the electrodes. An IMD may also be configured to store data about a patient's condition and the treatment delivered to the patient, which a clinician may wish to retrieve for analysis.
A clinician may use an external computing device, generally referred to as a programmer, to program parameters that are sent to the IMD or to receive and view data that is retrieved from the RID. The external computing device may be electrically coupled to an antenna device, sometimes referred to as a telemetry head, which converts the programmed parameters into wireless telemetry signals, such as radio frequency (RF) telemetry, signals, that are received by a corresponding telemetry antenna of the IMD. The telemetry head may also receive telemetry signals from the IMD that correspond to patient or treatment data, which is converted by the telemetry head into data usable by the external programmer.